meta-phosphor: entity-manager: fix ibm-power-cpu override

There is a missing fix from from Yocto OVERRIDE syntax change that
hasn't been noticed in a long while.  Fix it.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic40b65d328b4d8fa02f736948d7fde7981ba0669
diff --git a/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb b/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
index 848049b..efd0c48 100644
--- a/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
+++ b/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
@@ -23,7 +23,7 @@
 SYSTEMD_PACKAGES = "${PN} ${EXTRA_ENTITY_MANAGER_PACKAGES}"
 SYSTEMD_SERVICE:${PN} = "xyz.openbmc_project.EntityManager.service"
 SYSTEMD_SERVICE:fru-device = "xyz.openbmc_project.FruDevice.service"
-SYSTEMD_AUTO_ENABLE:fru-device_ibm-power-cpu = "disable"
+SYSTEMD_AUTO_ENABLE:fru-device:ibm-power-cpu = "disable"
 
 inherit pkgconfig meson systemd python3native